High-frequency discharge device



ly 1946- A. M. GUREWITSCH 2,404,226

HIGH FREQUENCY DISCHARGE DEVICE Filed Sept. '7, 1942 2 Sheets-Sheet 1Inventor Anatole M. Gur'ewitsch,

torney. 4

y 5, 1946- A. M. GUREWITSCH 3 HIGH FREQUEXCY DISCHARGE DEVICE FiledSept. '7, 1942 2 Sheets-Sheet 2 Inventor; Anatole M. Gurewlosch,

y Hm'btorney Patented July 16, 1946 HIGH-FREQUENCY DISCHARGE DEVICEAnatoleM. Gurewitsch, Schenectady, N. Y., assignor to General ElectricCompany, a corporation of New York Application September '7, 1942,Serial No..457,53-9

19 Claims.

My invention relates to electronic discharge devices and moreparticularly to high frequency electric discharge devices of thespace-resonant cavity type.

In the construction of electronic discharge devices for use in the highfrequency field, it is, of course, desirable to have a particularelectrode configuration which permits ready and suitable accessibilityto the electrode of the device, and which is arranged to utilize thesefeatures without sacrificing efficiency of operation. In accordance withthe teachings of my invention described hereinafter, I provide new andimproved arrangements in the construction of high frequency electronicdischarge devices which afford the advantages of the electrodeconstruction and configuration, and in addition offer greaterefficiencies than afforded by the prior art, arrangements.

It is an object of my invention to provide new and improved electronicdischarge devices.

It is another object of my invention to provide new and improved highfrequency electronic discharge devices of the space-resonant cavitytype.

It is a further object of my invention to provide a new and improvedelectronic discharge device construction wherein the electrodes of thedischarge device are spaced in substantial parallel relationship bymeans of insulating spacers, walls or cylinders, and wherein theresonant cavities are substantially enclosed by metal, thereby shieldingthe resonant cavities.

It is a still further object of my invention to provide new and improvedelectronic discharge devices which employ space-resonant cavities inconjunction with an electrode assembly which permits the operation ofthe devices Within the ultra-short wave length field such as severalcentimeters.

Briefly stated, in the illustrated embodiments of my invention I providenew and improved electric or electronic discharge devices of thespace-resonant cavity type wherein the electrodes of the dischargedevice are supported by a plurality of substantially parallel conductingmembers or disks which are maintained in the desired space relationshipby interposed insulating spacers, walls or cylinders sealed end-to-endwith respect to the members. Shielding means such as walls orpartitions, which may be integral with the outer membersor theintermediate member, and enclosed by the insulating cylinders establishwith the members spaceresonant cavities which are substantially enclosedby metal, thereby shielding the space resonant cavities and preventingthe radiation of electromagnetic energy through the dielectric materialconstituting theinsulating cylinders.

In accordance with another embodiment .of my invention, I provide inconjunction with the features above described, means readily adjustablefor controlling or establishing the natural resonance frequency of therespective cavities of the device. One form of the meanswhichaccomplishes the tuning may comprise ametallic collapsible type chamberwhich is sealed .to one of the cavities, and which is adjustable orcleformable in configuration to control the natural resonance frequencyof either the anode-grid cavity or the grid-cathodecavity by communicating therewith through openings in one of the members, or throughdielectric materials placed within the openings. The tuning means may,of course, be of rigid construction provided with adjustable metallicmeans to control the effective physical characteristics of the tuningchamber. For a better understanding of my invention, reference may behad to the following description taken in connection with theaccompanying drawings, and its scope will be pointed out in the appendedclaims. Fig. 1 of the accompanying drawings diagrammatically illustratesan embodiment of my invention as applied to a high frequency amplifier,and Fig. 2 is a cross sectional view of the arrangement shown in Fig. 1.Fig. 3 diagrammatically illustrates an embodiment of my invention asapplied to a high frequency oscillator; Fig. 4 diagrammaticallyillustratesan alternative arrangement for coupling the tuningchamber andone of the principal resonant cavities of the device; and Fig. 5 is afurther modification which may be used as an amplifier. Fig. 6 is afurther modification relating to an oscillator, and Fig. 7 represents astill further arrangement which may be applied to a frequency changer ormixer for energizing an intermediate-frequency stage of 'a highfrequency system. Figs. 8 and 9 diagrammatically illustrate othermodifications of my invention wherein the metallic walls which establishthe'spaceresonant cavities may be. supported by or attached to theintermediate member. Fig. 9a1s0 shows an arrangement wherein themetallic walls 7 which shield the resonant cavities are provided withtuned sections to minimize the amount of energy which is radiated fromthe respective cavities.

Referring now to Fig. 1 of the accompanying drawings, I provide a highfrequency electronic 7 3i discharge device of the space-resonant cavitytype. Although the construction and arrangement of Fig. 1 may beemployed for other purposes, in order to facilitate description of theinvention the device will be explained with particular reference tooperation as an amplifier. In carrying out my invention, I may employelectrode construction and terminal arrangements similar to thosedisclosed and claimed in a copending patent application Serial No.436,633 of James E. Beggs, filed March 28, 1942, and which isassignedtothe assignee of the present ap-' plication.

I provide a plurality of substantially parallel metallic walls ormembers I, 2 and 3 which are maintained in a substantially parallelrelation- 7 ship and which are centrally located with respect toelectrode. construction to be described presently. The members I, 2 and3 are preferably disks constructed of copper or brass and afiord readyaccessibility to the electrodeswhen used for ultra high frequencypurposes. Members I, 2 and 3 are maintained in a spaced relationship bymeans of. insulating walls or cylinders 4 and 5 which are interposedbetween the members I and 2, and 2 and 3, and are sealed in end-to-endrelationship to provide, at least in part, an

' evacuated enclosure for the device.. As will be ;obvious ,in view ofthe description appearing hereinafter, the regions or cavitie defined byprises a flanged cylinder I I terminated ina plate imity to a circularopening I3 in member 2. A conventional type heating element, such as afilament 14, may constitute a part of the cathode I0. Of course, thecathode construction may be sealed in a conventional way. Anelectrostatic control member, such as a grid I5, is conductivelyconnected to member 2 and constitutes the third element of theelectronic'discharge path. This control element is illustrateddiagrammatically and, if desired, the grid may be positioned along thelower edge of plate 2 in order to obtain the desired inter-electrodecapacity relationship.

In order to shield the space-resonant cavities, that is the anode-gridand the grid-cathode cavities, thereby providing regions which-aresubstantially-bounded by metal, I provide metallic walls or cylinders I6 and I1 enclosed by the insu- 'lating cylinders 4 and 5 and which maybe coaxial with the electrode construction described above. Cylinders I6and I'I may be made integral with members I', and 3, or may be formedseparately and attached thereto. It will be noted that cylinders I6 andI1 extend toward the intermediate member 2 and afford gaps I6 and- I1.

The principal effective capacitances of the respective cavities are,'ofcourse, determined by the by gaps I6 and I1 may be considered as shuntor by-pass c'apacitances. V

In orderv to tune the device, that is in order to control the naturalresonance frequency of one of the resonant cavities such as thatassociated with the anode 6 and the grid I5, I provide a tuning chamberI8 which may be defined by a metallic bellows-type member is. Thismember may be hermetically sealed'to member -I and may be readilyattached thereto by a welding or soldering operation.

If desired, plate I may be provided with a cylindrical flange 2i? towhich the member !9 is fastened. r

The tuning operation may be effected by controlling the dimensions ofmember I9. As a way of diagrammatically illustrating the adjustment ofthe dimensions of member I9, I have chosen to illustrate a thumbscrewassembly 2i, which is supported from memberl by an arm 2i, which raisesand lowers the top thereof, thereby varying the dimensions-of the tuningcavity. Input electrode means, such as a concentric line 22, may bepositioned as illustrated in the drawings and arranged to be incommunication with the gridregion defined by members 2 and 3 and com- I2'of emissive material positioned in close proX- cathode cavity. Ofcourse, since it is desired to maintain the cavity at a low pressure,this line may be sealed by a conventional glass bead. I also provideoutput electrode means responsive to the electromagnetic waves of theanode-grid cavity. and in the particular embodiment illustrated theoutput electrode means which constitutes a concentric line 23 is shownsupportedfby the member I9. Of course, since the tuning chamber is incommunication with the anodegrid resonant cavity, the frequency of theelectromagnetic waves of the anode-grid cavity are also present in thetuning cavity.

Reference may be had to 2 to. obtain a 7 more explicit concept of themanner in which the grid I5'is positioned relative to the electrodeconproper operation, one of the cavities may be de-' signed so that itsnet reactance is slightly capacitive, and the other designed so that itsreactance is slightly inductive for the desired operating frequency.

, anode-grid resonant cavity and the grid-cathode parallel or projectedareas, between members I,

2 and 2,3, The effective capacitances provided cathode cavity byenergization of the input eleci trode means 22, the potential of thegrid I5 undergoes highfrequency cyclic variations thereby controllingthemagnitude of the electromagnetic waves within the anode-grid cavity dueto the fact that the anode undergoes amplified cyclic 7 Voltagevariations, The output electrode means 23 is thus energized and thisoutput electrode In connection with the general principles of 5 meansmay be connected to any suitable utilization circuit.

i 'The eflective resonance frequency of the device may be controlled oradjusted by means of the thumbscrew assembly 21. the collapsible memher[9 is varied in height, the natural resonance frequency of the deviceisvaried'.

Fig; 3 diagrammatically illustrates another embodiment of my inventionas applied to an electric discharge device embodying the principles ofmy invention, and which may be employed as an oscillator. In thisarrangement, the elements hav been assigned reference numeralscorresponding to similarly disposed elements of Fig. 1. Where it isdesired to confine the evacuated enclosure to the region between members"I and 3, suitable dielectric sealing partitions or windows may beplaced within the holes or openingst and. 9, thereby making itunnecessary to seal the tuning chamber. For example, glass insulatingwindows 24 and '25 may be positioned within the openings and theseopenings in themselves pro vide communication between the anode-gridcavity and the tuning cavity. However, in order to obtain more effectivecoupling, I may employ metallic conductors 26 and 2'! in the form ofloops extending through and sealed to the windows 24 and 25 and fastenedat their extremities to the metallic member l on opposit sides thereof.

The tuning chamber may comprise a rigid metallic cup 2-8 of cylindricalcross section and maybe tuned by an adjustable metallic member, such asa metallioscrew 29. Output electrode means, such as a concentric line30, is connected to the tuning chamber or may be connected to theanode-gridresonant cavity.

Upon the application of a suitable unidirectional voltage to the anode 6and cathode I through members I and 3', theelectronic device willoscillate at a frequency determined by its dimensions Of course, themagnitude of the frequency may be controlled by adjustment of screw 29.

In operation, it will be appreciatedthat the feed-back or couplingbetween the anode-grid cavity and the grid-cathode cavity is obtained byvirtue of the inter-electrode capacity and by the design of thedimensions of the respective cavities. This feed-back voltage ma be"made to have the requisite magnitude and the desired phase to sustainthe device in oscillation. In certain instances it may be desirable toprovide an additional coupling between the anode-grid and thegrid-cathode cavities. For example, openings or windows maybe placedbetween these cavities and, if desired, may be provided with conductivecoupling means. Electromagnetic energy is interchanged between theanode-grid cavity and the tuning chamber through loops 26 and 21.

In Fig. a, an alternative arrangement of the coupling between theanode-grid cavity and the tuning chamber is illustrated. Instead ofusing a loop, it will be appreciated that a probe constructioncomprising a linear metallic conductor 3| may be employed. Thisconductor, of course, is sealed in the insulating window 25.

It will be readily appreciated that apparatus built in accordance withmy invention may be applied with equal facility to devices employingother arrangements'oi the output electrode construction. For example, inFig. 5 the output electrode means comprising a concentric trans missionline 32 is shown as extending into the anode-grid cavity through theshieldingv wall Hi.

In such an arrangement, it may be preferable to increase thediameter ofthe insultaing and spaci-ng cylinder-33 which maintains members I and Zin spaced relation. It, of course, will be appreciated that this.electrode construction is readily adaptableto high frequencyelectronlcrdis charge devices generally, which includes amplifiers,oscillators, frequency changers, etc.

In Fig. 6, I have there illustrated a still further embodiment of myinvention wherein the anode, cathode and the grid structure of thedischarge pathare maintained in the desired space relation by employingthe shielding walls in conjunction with alined insulating means such asrings. More particularly, the anode assembly maybe supported byametallic member of cylindrical cross section and constitutes an anode 35which is supported bya spoke or arm construction similar to that shownin Fig. 2. The member 34 is also provided with a metallic tubular wall36 which defines the anode-grid resonantlcavity. The anode-grid cavitymay be coupled with a rigid metallic tuning chamber 3"! through dielectric windows 38 and 39 which aresea-led to mom'- ber 34. A grid 40 issupported in spaced relation with respect to anode 3 5 and the cathode,to be described hereinafter, by means of a metallic plate or disk 41 andwhich is insulated from member 34 by means of an insulating or glassring 42. Of course, member 34 and ring 42 are sealed to provide anevacuated space for-the electronic discharge path. A cathode 43 issupported by a metallic cup 44 of cylindrical cross section and is alsomaintained. in spaced relation with respect to the disk 4| by means ofan insulating or glass rin 45. Rings 42 and 45 'areof small axialdimension relative to the axial length. of the device so that arelatively smallarea, 'definedfby a dielectric materiaLis associatedwith the anodegrid' andthe grid-cathode space-resonantcavities. In thisparticular embodiment of my invention, the space defined by members 34and. 44 is main tamed at. a partial vacuum and the cathode 43 may besealed in a proper manner to obtain best results. The natural resonancefrequencyof the electronic discharge device maybe controlled by means ofthe tuning chamber defined by memher 3.1 and may be provided with anadjustable metallic member 46, th position of which within the tuningchamber may be established by any suitable mechanical expedient.

Output electrode means may be inserted into the anode-grid cavity andmay comprise a cone centric line 4.! which is sealed to maintain thedesired partial vacuum within the device.

Upon the application of a suitable unidirectional voltage to the anodeand the cathode of the device illustrated in Fig. 6, the system willoscillate at its natural resonance, frequency which may be adjusted. bymeans of member 46 and the tuning chamber. As stated above, in this typeof embodiment of my invention the coupling between the anode-grid andthe grid-cathode cavities to produce the desired feed-back is accomplished by the interelectrode capacity of the elements constituting theelectronic discharge path.

'Fig. 7 diagrammatically illustrates a still further embodiment of myinvention. which may be employed as a frequency changer or mixer. 'A

plurality of conductive or metallic disks 48;;49

and'iiii are maintained in spaced relation bymeans of insulatingcylinders" 5! and 52 which are sealed to members 48-49 and 49'- 50,respectively, and provide in part an enclosed evacuated region withinwhich the elements of the electronic discharge path arepositioned.Metallic shielding walls -5-3 and 54. establish with disks 48-50space-resonan cavities substantially bounded by metal to localize thefields within these cavities. These walls may be integral with disks 48and 50 or'may be formed separately and attached thereto. An anodeextends into the region defined between disks 48 and 49 and may besealed'thereto. This anode may be constructed of solid metal; Grid 56 issupported by and conductively connected to disk 49. and constitutes thesecond electrode of the discharge path. A cathode 51 may be placed inclose proximity to grid 56 and extends into the grid-cathode cavityspace through an opening in disk 50.

In this modification of my invention, the tuning' chamber may beassociated with the gridcathode resonant cavity by means of holes, oropenings 58 and 59. The tuning cavity may comprise a sealed collapsibleor bellows-type metallic member 60 comprising two cylindricalcollapsible as for example in an arrangement for energizing I anintermediate frequency stage of a high frequency system, the anode 55and grid 56 may be connected to an.output circuit 66 in the mannerillustrated where the anode is connected to the circuitj'fifi and thegrid, is also connected to the circuit through disk 49, and acylindrical or tubular conductor Bl, thereby-affordingreadily acjcessibleelectrodes for high frequency purposes.

'.Upon. the application of suitable unidirectional voltage to theanodeand cathode and upon the impression of high frequency excitation'tothe input electrode means 65, th device'of Fig. '7 will operate totransmit to circuit 66 high frequency oscillations which are of a beatfrequency determined byrthe frequency of the input excitation V and thenatural resonance frequency at which 4;

the discharge device operates. The natural resonance frequency at whichthe device operates is determined principally by the dimensions of thedevice, particularly theanode-grid and the gridcathode cavities.

natural resonance frequency and the frequency of the input excitationAdjustment of the tuning chamber controlsthe natural resonance frequencyof the device and consequently permits The device, of course, operatesin accordance with the difference between its,

grid'and the grid-cathode cavities may be defined by metallic wallswhich extend from the intermediate member to the end or outer members.For example, in Fig. 8 the disks, B9 and'lllare maintained in a spacedparallel relation by insulating cylinders II and'lZ. Disk 58 supports ananode 13 which maybe generally similar to the supporting arrangementshown in Fig. 2. A grid H is supported by disk 69 and the-cathode 15 ismaintained in proximity to grid 14. A coupling between the anode-gridcavity and the tuning chamber (not shown) may be effected by means ofprobes 16 and H which may be sealed in Windows I8 and (9. r

The disk may be provided with cylindrical shaped metallic walls and 8|which extend to,-

tial impedance in order to prevent the loss of appreciable energy. InFig. 9 walls 80 and 8| are provided with tuned transverse extensionssuch as rims or flanges 82 and 83 which may extend toward the axis ofthe device, or may extend away from the axis, and which are proportionedand designed to afford a maximum impedance or a tuned line effect toprevent the transmission of appreciable energy bymeans of theelectromagnetic waves through the gaps. r

While I have shown and described my invention as applied to a particularsystem-and as embodyingvarious devices diagrammatically shown, it willbe obvious to those skilled in the art that changes and modificationsmay be made without adjustment of the frequency of the current suppliedto circuit 66.

' r In view of the above disclosures, it will be appreciated that Iprovide improved high frequency.

electronic discharge devices which permit the use of desirable electrodearrangements suitable'for high frequency purposes, and which also obtaina high efficiency by localizing the electromagnetic fields of thespace-resonant cavities associated with the electrodes of the dischargepaths. In other words, the space-resonant cavities are shielded orenclosed by metaL'thereby reducing the amount of energy which wouldotherwise be lost by passage of the electromagnetic waves bodiment of myinvention whereinthe anodedeparting from. my invention, and I thereforeaim in the appended claims to cover all such changes and modificationsas fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is: 7

1. A high frequency electronic discharge device comprising electrodesincluding an anode, a cathode and a grid, a plurality of metallicmembers spaced in parallel relationship and each being conductivelyconnected to a different one of said electrodes, the outer members eachcomprising a metallic wall extending toward but not engaging theintermediate member and providing cavity resonators substantiallybounded by metal, and

l insulating walls supporting said metallic members andsealing saiddevice to form an evacuated enclosure for said metallic walls and forsaid electrodes. I

2. A high frequency electronic discharge device comprising electrodesincluding an anode, a cathode and a grid, a plurality of metallicmembers spaced in parallel relationship and each being conductivelyconnected to and supporting a dif- 3. A high frequency electronicdischarge device 7 comprising electrodes including an anode, a cathodeand a grid, a plurality of metallic members' "spaced in parallelrelation, insulating walls spaced "9'; inend-to-end relation betweensaid members providing an enclosure for said electrodes, metallic wallmembers enclosed by said insulating members' providing cavity resonatorssubstantially bounded by metal and adjacent the anode-grid andgrid-cathode electrodes of said device, and electrode means connected toone of said cavity resonators.

4. A high frequency electronic device comprising electrodes including ananode, a cathode and a grid, a plurality of metallic members spaced inparallel relation, a pair of insulating cylinders spaced in end-to-endrelation between said meme bers providing an enclosure for saidelectrodes, metallic walls enclosed by said insulating cylindersproviding cavity resonators substantially bounded by metal: andadjacent. the anode-grid and grid-cathode electrodes of said device,-and electrode means connected to the anode-gridcavity resonator.

5. A high frequency electronic device comprising electrodes including ananode, a cathode and a grid, three metallic members spaced in parallelrelation and supporting said electrodes, a pair of insulating cylindersspaced in end-to-end relation between said members providing anenclosure for said electrodes and maintaining aid electrodes in spacedrelation, metallic, walls enclosed by said insulating cylindersproviding cavity resonators adjacent the anode-grid and grid-cathodeelectrodes of said device, and means connected to one of said resonatorsfor controlling the natural frequency of one of said resonators.

6. A high frequency electronic device comprising electrodes including ananode, a cathode and a grid, three metallic members spaced in parallelrelation and supporting said electrodes, a pair of insulating cylindersspaced in end-to-end relation between said members providing anenclosure for said electrodes and maintaining said electrodes in spacedrelation, metallic walls enclosed by said insulating cylinders providingcavity resonators adjacent the anode-grid and grid-cathode electrodes ofsaid device, and means comprising a tuning chamber connected to theanode-grid resonator for controlling the natural frequency of theanode-grid cavity resonator.

'7. A high frequency electronic device comprising electrodes includingan anode, a cathode and a grid, three metallic members spaced inparallel relation and supporting said electrodes, a pair of insulatingcylinders spaced in end-to-end relation between said members providingan enclosure for said electrodes and maintaining said electrodes inspaced relation, the outer members being provided with metallic wallsenclosed by said insulating cylinders providin cavity resonatorsadjacent the anode-grid and grid-cathodev electrodes of said device, andmeans connected to one of said resonators for controlling the naturalfrequency of the grid-cathode cavity resonator.

8. A high frequency space resonant system including an electronic devicecomprising electrodes, a series of circular metallic members, saidmembers being in parallel spaced relation, a plurality of insulatingcylinders sealed in end-to-end relation between said members providingan enclosure for said electrodes, substantially cylindrical metallicpartition spaced concentrically with respect to and enclosed by saidinsulating cylinders and coaxial with the electrodes of said devicedefining substantially metallic bounded cavity resonators, meansforestablishing a difference of potential between two of the electrodesr l0 constituting an anodeand. a cathode, andout'put means coupled toone of said cavity resonators.

9. A high frequency electronic device comprising electrodes including ananode, acathode and a grid; three metallic members spaced in parallelrelation, 3, pair of insulating cylindersv sealed in end-to-end relationbetween said members pro.- viding an enclosure for said, electrodes,metallic walls enclosed by said insulatin cylinders providing cavityresonators substantially boundedv by metal, means establishing a spaceof adjustable dimensions, in communication with the anode-grid cavityresonator to tune thelatter,

and output means connected to the last men-' tioned means.

10.. A high frequency space resonant system including an electronicdevice comprisingelectrodes including an anode, a cathode and a grid,three circular metallic disks, said disks being in parallel spacedrelation, a pair of insulating cylinders sealed in end-to-end relation.between said disks providing an. enclosure for the electrodes, the outerdisks being provided with metallic extensions concentric with the axialdimension of said device and enclosed by the insulating. cylindersproviding .a pair of cavity resonators. ad-

J'acent the anode-grid and grid-cathode electrodes of saidelectronicdevicameans connected thereto for establishing a difference inpotential between said anode andsaid cathode, and output means.connected to one of. said resonatorsresponsive to theelectricaloscillations established in the anode-grid cavity resonator.

11, A high frequency electronic device comprising electrodesincludingran anode, a cathode and a grid, three metallic memberscentrallylocated with respect to said electrodes. said members beng inparallel. spaced relation and constituting externally accessibleterminals forsaid electrodes,

connected to the grid-cathode cavity resonator,

and output means connected to said housing.

12. A high frequency electronic device comprising electrodes includingan anode, a cathode and grid, three metallic members centrally locatedwith respect to said electrodes, said members being in parallel spacedrelation and constituting externally accessible terminals for saidelectrodes, a pair of insulating cylinders sealed in end-to-end relationbetween and to said members providing a part of an evacuated enclosurefor said electrodes, the outer members bein provided with metallic wallssubstantially perpendicular to the planes of said members and en.-closed by said insulating cylinders providing a pair of cavityresonators substantially bounded by metal, input means connected to thegridcathode cavity resonator, and output means in said anode-grid cavityresonator.

13. A high frequency electronic device comprising electrodes includingan anode, a cathode and a grid, a plurality of metallic membersat leastthree in number, said members being in parallel spaced relation andhaving externally 11 t accessiblesurfaces providing symmetrical highfrequency terminals fromsaid electrodes, said anode and saidcathodebeing connected respectively to the outer members and said grid beingconnected to the intermediate member, a pair of insulating cylinderssealed in end-to-end relation between said members providing a part ofthe enclosure for said electrodes, the said outer members bein providedwith conductive walls en-V closed by said insulating cylinders forminganodeg'rid and grid-cathode cavity resonators which are substantiallybounded by metal, means comprising an adjustable metallic bellows-typemember' sealed to the member connected tosaid anode and communicatingwith said anode-grid cavity resonator through op eningsin said outermember; input'means connected to the grid-cathode cavity resonator, andoutput means extending into said bellows-type member. 14: An evacuateddevice comprising three substantially parallel conductive disks, one ofthe outer. disks and the intermediate disk constituting alcav'ityresonator and said intermediate disk and the other outer diskconstituting a second cavity resonator, a pair .of insulating cylindersmain- I taining said disks in spaced relation, electric disl5.' 'A highfrequency electronic amplifier com.-' prising electrodes including ananodeQa cathode and a grid, a plurality of metallic members spaced in"parallel relation, a pair of insulating Walls spaced inend-tO-erldrelation between said members providing an enclosure for saidelectrodes, metallic walls enclosedby saidinsulating walls prbvidingcavity resonators substantially bounded by 'metal and coupled with theanode-grid and grid-cathode electrodes of said device, input meansconnected to the grid-cathode resonator, and output means connected tothe anode-grid cavity resonator for deriving energy from the anode-gridcavity resonator.

-"l6.' A high frequency electronic discharge device' comprisingelectrodes including an anode, a cathode and a grid, a plurality ofmetallic members spaced in parallel relation, insulating walls spaced inend-to-end relation between said members providing an enclosure for theelectrodes, and-metallic wall members enclosed by said insulating wallsproviding cavity resonators substantially bounded by metal and adjacentthe anodegrid and'the grid-cathode electrodes of said device, saidmetallic walls having a configuration which minimizes the transfer ofenergy from the cavity resonators to the region bounded by theinsulating walls.

l7; 'A high frequency electronic discharge 'device comprising electrodesincluding an anode, a

cathode and a grid, a'plurality of metallic members spaced in parallelrelation, insulating Walls in end-to-end relation between said membersproviding an enclosure for said electrodes, metallic wall membersenclosed by said insulating walls and supported by the intermediatemember and extending toward but not. engaging the outer membersproviding cavity resonators substantially bounded by metal and adjacentthe anodegrid and the grid-cathode electrodes of said device, saidmetallic wall members being provided with tuned transverse extensions tominimize the transfer of electromagnetic energy from said cavityresonators to the region bounded by said insulating walls andsaidfmetallic wall members.

18. A high frequency electronic'device compris- 7 ing threesubstantiallyparallel conductive members, one of the outer members and theintermediate member constituting a cavity resonator, a metallic memberconnected to said outer member external of said resonator and formingtherewith a substantially" closed housing'coupledto said resonator forhigh frequency currents, adjustable means connected to said metallicmember for controlling the natural resonance frequency of saidresonator, said intermediate member and the other outer memberconstituting a second cavity resonator, electricdischarge meanswithin'said device and, comprising electrodes including. an

anode connected to the first of said outer -mem-' electron emittingsurface within the vicinity of said intermediate member, a gridsupported by said intermediate member, an anode conductively connectedto the other outer member and extend, ing into theregion defined betweensaid other outer memberand said intermediatemember, an

adjustable metallic bellows-type member con-' 'nected to one of saidparallel member s forming therewith a substantially closed housing, saidhousing constituting a part of said device for'controlling the naturalresonance frequency, said one parallel member being provided withopenings to permit transfer of energy to said housing by means ofelectrical oscillations, and output means within said housing forderiving energy therefrom. I v

r ANATOLE M. GUREWITSCH.

